Static on call handler

[hartgravesc1]

Hello, we are having an issue where customers are calling our main call handler, and the entire time they are hearing static. They eventually get transferred to a representative at which point the caller is connected, but after a few seconds the call drops. I've put in a ticket with our TSP for now. Any thoughts?

[Jaime Valencia]

What do you use to connect to the PSTN?? PRI? FXO? SIP?

Does this happen to internal calls?

What troubleshooting has been done?

[hartgravesc1]

We have 4 T1 PRI's, where 2 PRI's go into a 2911 voice gateway which go to our primary and the the other 2 go into another 2911 voice gateway which go into our secondary.

This is not happening with internal calls.

I'm honestly not sure where to begin with troubleshooting.

[Bra2193495]

I would make an internal call to the call handler just to verify that it is not something on the call handler (doubtful) then start working your way back to the carrier. I suspect a carrier issue.

Have you done any debugging/packet captures on your gateways to determine if the disconnect is being initiated by your internal equipment or the carrier?

Can you induce a failover to your secondary gateway and see if your are still having the issue?

[hartgravesc1]

Internal call to call handler (where I eventually get to a representative) sounds crystal clear with no drops.

I have not done any debugs on my gateways yet. Is there a specific one that will show a call in progress being disconnected?

I am wondering how to induce a failover. I'm guessing I could unplug the PRI's from one gateway and the TSP MUX will send the calls to a working PRI.

[Bra2193495]

I would fail over to the working PRI and see if that makes a difference. That will narrow your scope down.

As far as a debug goes, everything I deal with is SIP from my carriers and I never had to learn much else. I am sure there is a debug that will let you see what is going on on a PRI, I just do not know it off the top of my head.

If you handoff to your network on SIP you *might* be able to get some information from 'debug ccsp calls', but that would jsut give you info about what is coming out of the gateway and not what is going in.

[HARIS_HUSSAIN]

• Just make a test call and collect following details.

show call active voice 

  ==> Look for packet drops and/or VAD/Comfort Noise Generation via DSP

• To Disable the Primary PRI you can shut down the controller or Interface Serial :23 on Primary Router.

controller t1 0/0
 shutdown

• Try to disable VAD on dial-peers pointing towards CUCM.
• And Don't Forget to rate and mark correct if found so <<

Thanks

Haris

[hartgravesc1]

Thanks for commenting. After our carrier finally reached out, they admitted that they are seeing some problems with their system. They are looking into it now.